Tuning terahertz transitions in cyclo[n]carbon rings

TL;DR

This paper presents an analytic model for cyclo[n]carbon rings that predicts tunable terahertz gaps and optical transitions, proposing a new approach for THz emission using these molecules.

Contribution

The paper introduces a simple analytic model for cyclo[n]carbon rings that describes tunable THz gaps and optical transitions, including effects of symmetry-breaking and external electric fields.

Findings

The THz gap size can be modulated by external electric fields.

Optical transition strengths across the gap are tunable.

A new THz emission scheme based on cyclo[n]carbon is proposed.

Abstract

We develop an analytic model for an ideal polyyne ring which describes the induced THz gap in the molecular spectrum due to the Stark effect. This simple model can also be used to describe an odd-dimered cyclocarbon which has undergone a spontaneous symmetry-breaking event (due to the Jahn-Teller effect) as an effective dipole across an ideal ring. We show that both the size of the gap, and the strength of optical transitions across it, can be modulated by varying the external electric field strength. A THz emission scheme based on optical excitation is proposed, thus paving the way for a new class of THz emitters based on cyclo[n]carbon.